EPITHELIAL CHANGE/GENE EXPRESSION IN CROHN'S DISEASE

肠上皮代表粘膜免疫系统和内腔环境之间的主要界面。SAMP 1/Yit小鼠是一种遗传近交系小鼠，其发展回肠炎，其类似于人克罗恩病，在30周龄时几乎完全消退。SAMP/Yit小鼠疾病的主要特征是回肠上皮的显著结构异常，其发生在炎症和回肠炎发展的早期。回肠炎在无菌SAMP/Yit中不发展，表明腔内细菌或环境产生的上皮损伤在慢性回肠炎症的发展中的作用。这些观察结果提出了这样的假设，即SAMP 1/Yit小鼠对损伤具有改变的上皮反应，这导致异常，这反过来又导致慢性肠炎症。目的1将检查与对照小鼠相比，SAMP/Yit小鼠对上皮损伤的反应是否改变。将检查上皮干细胞命运的关系。连续转移技术将用于区分SAMP 1/Yit上皮固有的损伤反应差异与活化T细胞和炎症反应诱导的变化。还将检查调节隐窝上皮细胞凋亡的基因表达的变化。在目标2中，我们将确定SAMP/Yit小鼠中存在的上皮结构或分化的变化是否诱导调节炎症反应的分子的上皮产生的改变。将在从患有回肠炎的小鼠中分离的上皮细胞中检查上皮衍生的细胞因子的产生，所述上皮细胞来自上皮细胞性质的可遗传改变或由炎症和进行中的上皮损伤诱导的上皮细胞性质的改变。在目标3中，我们将研究上皮表达基因的遗传差异，这些基因可能参与SAMP/Yit小鼠回肠炎的发生。这将使用cDNA微阵列技术来完成，以鉴定与通过项目2中概述的遗传分析确定的疾病易感性或发展相关的染色体位点编码的差异表达基因。

The intestinal epithelium represents the major interface between the mucosal immune system and the lumenal environment. The SAMP1/Yit mouse is a genetically inbred mouse line that develops ileitis that is similar to human Crohn's disease with near complete penetrance by 30 weeks of age. A major feature of disease in the SAMP/Yit mouse is the prominent architectural abnormalities of the ileal epithelium that occur early in the development of inflammation and ileitis. Ileitis does not develop in germ free SAMP/Yit suggesting a role for lumenal bacteria or environmentally-produced epithelial damage in the development of chronic iteal inflammation. These observations raise the hypothesis that SAMP1/Yit mice have an altered epithelial response to injury which results in abnormalities which, in turn, leads to chronic iteal inflammation. Aim 1 will examine whether SAMP/Yit mice have an altered response to epithelial damage compared to control mice. The relationship of epithelial stem cell fate will be examined. Adoptive transfer techniques will be used to separate differences in injury-response that are intrinsic to the SAMP1/Yit epithelium from changes induced by the presence of activated T-cells and an inflammatory response. Changes in the expression of genes which regulate crypt epithelial apoptosis will also be examined. In aim 2 we will determine whether the changes in epithelial architecture or differentiation present in the SAMP/Yit mouse induce alterations in epithelial production of molecules that regulate the inflammatory response. The production of epithelial derived cytokines will be examined in n epithelial cells isolated from mice with ileitis and from heritable alterations in the properties of the epithelial alterations in the properties of the epithelial cells or are induced by inflammation and ongoing epithelial damage. In aim 3 we will examine heritable differences in epithelial expressed genes that may be involved in the development of ileitis in the SAMP/Yit mouse. This will be accomplished using cDNA microarray technology to identify differentially expressed genes that are encoded with chromosomal loci associated with susceptibility or development of disease as determined through the genetic analysis outlined in project 2.